1. Field of the Invention
The present invention relates to electronic circuits, and more particularly, to techniques for sensing temperature on a circuit and automatically calibrating temperature sensing circuits to compensate for process, temperature, and supply voltage variations.
2. Description of the Related Art
The operating temperature of an integrated circuit (IC) can significantly effect its performance. A significant change in the operating temperature of an IC can cause the IC to operate outside desired performance specifications. Temperature sensing devices have been developed to monitor the operating temperature of integrated circuits so that performance characteristics can be more tightly controlled.
Traditionally, the temperature of an integrated circuit die is sensed with a temperature sensing diode (TSD) and an off-chip temperature sensor. The TSD is a PN junction diode. The two terminals of the diode, which is located in the corner of the die, are routed to a pin to work with the off-chip temperature sensor.
Off-chip temperature sensors require large components that are external to the integrated circuit. Many of today's integrated circuit die contain a large number of pins that require numerous external components. Because board space is usually limited, there is a need to provide techniques for sensing the temperature of an integrated circuit, while reducing the number of external components.